JP5250635B2 - Polymerizable liquid crystal composition, vertical alignment liquid crystal film using the same, and method for producing the same - Google Patents

Description

  The present invention relates to a polymerizable liquid crystal composition containing a polymerizable reactive vertical alignment liquid crystal mixture solution and a primary or secondary amino coupling agent, a vertical alignment liquid crystal film using the same, and a method for producing the same.

Generally, liquid crystal types can be classified into rod-type liquid crystals and discotic liquid crystals when classified according to the pattern. A substance in which at least two of the three-dimensional refractive indexes _nx , _ny , and _nz of the substance are different from each other is called a birefringent substance, and a direction in which there is no phase difference of linearly polarized light in the incident direction. Is defined as the optical axis. In the rod-like liquid crystal, the long axis direction of the molecule is the optical axis, and in the discotic liquid crystal, the shortening direction of the molecule is the optical axis.

  Among these, the alignment state of the rod-like liquid crystal is large and can be classified into five types as follows. First, the planar orientation refers to an orientation in which the optical axis is parallel to the film plane, and secondly, the homeotropic orientation is the case where the optical axis is perpendicular to the film plane, i.e., the normal of the film. Third, the tilted orientation refers to an orientation in which the optical axis is inclined at a specific angle between 0 ° and 90 ° with respect to the film plane.

  Fourthly, the spray orientation refers to an orientation in which the optical axis continuously changes at an inclination angle of 0 ° to 90 °, or a minimum value within a range of 0 ° to 90 °. Fifth, cholesteric The (cholesteric) orientation is similar to the planar orientation in which the optical axis is parallel to the film plane, but the more the light travels in the thickness direction, the more the optical axis rotates clockwise when observing from the direction perpendicular to the plane. Alternatively, it refers to an orientation that rotates counterclockwise by a certain angle.

  Among them, the second vertically aligned liquid crystal film is TN (Twist Nematic) mode, STN (Super Twist Nematic) mode, IPS (In Plane Switching) mode, VA (Vertical Alignment) by itself or in combination with other films. ) Mode and OCB (Optically Compensated Birefringence) mode, etc., it can be used as an optical film such as a retardation film and a viewing angle compensation film. Usually, a thin alignment film is coated with an alignment agent. The liquid crystal is coated after the formation.

  In order to attach the vertically aligned liquid crystal film to the polarizing plate for the purpose of improving the brightness or compensating for the viewing angle, the gap between the rollers facing each other at a fixed interval as in the polarizing plate manufacturing process is required. A roll-to-roll operation, which is crimped while passing through, should be performed. For this purpose, it is preferable to use a plastic base material that is flexible to pressure and slight impact.

  There are several proposals for forming vertically aligned liquid crystals on such plastic films.

  US 6,816,218 B1 (Patent Document 1) describes the use of an aluminum film deposited on a plastic substrate as a vertical alignment film. In this case, aluminum adheres weakly to the surface of the plastic substrate, so that part of the aluminum is removed at the time of peeling, causing a defect.

  EP 1376163 A2 (Patent Document 2) describes that a liquid crystal solution having a horizontal or cholesteric alignment is coated on a plastic substrate and then used as an alignment film to realize a vertically aligned liquid crystal thereon. Yes. However, in this case, there is a problem that the degree of vertical alignment of the liquid crystal layer is determined according to the degree of curing of the liquid crystal used as the alignment film.

  US 20060278851 (Patent Document 3) and JP 2006-126757A (Patent Document 4) present a film in which a primary aminosilane-based coupling agent is added to a vertically aligned liquid crystal solution to increase adhesion. Has been. However, such a primary aminosilane-based coupling agent has a weak point that it deteriorates the orientation of the liquid crystal and lowers the transparency.

  In KR 2005-0121835 (Patent Document 5), a polymerizable reactive liquid crystal mixture solution containing a predetermined surfactant is made hydrophilic on the surface without separately using an alignment film for inducing vertical alignment of liquid crystals. A vertically aligned liquid crystal film was manufactured by coating on a treated plastic substrate. However, there is a big problem in the adhesive force between the liquid crystal and the substrate, and the liquid crystal alignment is fundamentally unstable, and various defects are caused thereby.

US Pat. No. 6,816,218 European Patent Application No. 1376163 US Patent Application Publication No. 20060278851 JP 2006-126757 A Korean Published Patent No. 2005-0121835

  The present invention has been derived in order to solve the above-mentioned problems, and is a polymerizable liquid crystal that has excellent adhesion and can produce a stable vertically aligned liquid crystal film on a substrate with or without an alignment film. It aims at providing the manufacturing method of the vertical alignment liquid crystal film using the composition and the said polymeric liquid crystal composition.

  Another object of the present invention is to provide a vertically aligned liquid crystal film manufactured by the method and a liquid crystal display device including the vertically aligned liquid crystal film.

  In order to achieve the above object, the present invention provides a polymerizable liquid crystal composition comprising a polymerizable vertical alignment liquid crystal mixture solution capable of polymerization and a primary or secondary amino coupling agent.

  The present invention also provides a polymerizable liquid crystal composition comprising a polymerizable vertical alignment liquid crystal mixture solution capable of polymerization and a primary or secondary amino coupling agent on a plastic substrate having a hydrophilic surface. A method for producing a vertically aligned liquid crystal film including a coating step is provided.

  The primary amino coupling agent may be represented by the following chemical formula 1.

In Formula 1,
R ¹ is an alkyl group having 1 to 20 carbon atoms, and the terminal —CH ₃ in the alkyl group may be substituted with —NH ₂ ;
R ² is a single bond or an alkylene group having 1 to 20 carbon atoms. In the alkylene group, 1 to 2 —CH ₂ — that are not adjacent to each other are —O—, —C (═O) —, -NH-, -CH = CH-, -CONH-, which may be substituted with a cycloalkylene group having 3 to 8 carbon atoms or an arylene group having 6 to 10 carbon atoms. The hydrogen of may be substituted with an alkyl group having 1 to 4 carbon atoms.

  The secondary amino compound may be represented by the following chemical formula 2 or chemical formula 3.

In Formula 2,
R ³ and R ⁶ are each an alkyl group having 1 to 20 carbon atoms, in which the terminal —CH ₃ is substituted with —NH ₂ or —Si (R ′) _n (OR ″) _{3 -n.} R ′ and R ″ may be the same as or different from each other, each is an alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2,
R ⁴ and R ⁵ are each a single bond or an alkylene group having 1 to 20 carbon atoms, and 1 to 2 —CH ₂ — that are not adjacent to each other in the alkylene group are —O— and —C (═O) —. , -NH-, -CH = CH-, -CONH-, a cycloalkylene group having 3 to 8 carbon atoms, or an arylene group having 6 to 10 carbon atoms, and any hydrogen in the arylene group may have a carbon number May be substituted with 1 to 4 alkyl groups,

In Formula 3,
R ⁷ , R ^8, and R ⁹ are each an alkylene group having 1 to 20 carbon atoms, and 1 to 2 —CH ₂ — that are not adjacent to each other in the alkylene group are —O—, —C (═O) —, -NH-, -CH = CH-, -CONH-, a cycloalkylene group having 3 to 8 carbon atoms or an arylene group having 6 to 10 carbon atoms may be substituted, and any hydrogen of the arylene group may have 1 carbon atom. May be substituted with ~ 4 alkyl groups.

  According to the present invention, by adding a primary or secondary amino coupling agent to a conventional polymerizable reactive vertical alignment liquid crystal mixture solution, a stable vertical alignment liquid crystal can be obtained regardless of the presence or absence of an alignment film. Since a film can be manufactured, productivity can be improved.

It is a vertical sectional view of a vertically aligned liquid crystal film manufactured on a plastic substrate. 4 is a diagram illustrating a change curve of a retardation value according to a viewing angle of a vertically aligned liquid crystal film obtained in Example 1. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by Example 3. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by Example 5. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by Example 7. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by the comparative example 1. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by the comparative example 2. FIG. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by the comparative example 3. It is a figure which shows the change curve of the phase difference value according to the viewing angle of the vertical alignment liquid crystal film obtained by the comparative example 4.

  Hereinafter, the present invention will be described in more detail.

  In the present invention, the general structure of the primary amino coupling agent used by mixing in the polymerizable reactive vertically aligned liquid crystal mixture solution can be represented by Formula 1.

  Specific examples of preferred primary amino coupling agents include methylamine, ethylamine, 1-propylamine, and 2-propylamine. 1-butylamine, 2-butylamine, 3- (dimethylamino) propylamine (3- (dimethylamino) propyl amine), and the like, but are not limited thereto. It is not a thing.

  In the present invention, the general structure of the secondary amino coupling agent used by mixing in the polymerizable reactive vertically aligned liquid crystal mixture solution can be represented by the chemical formula 2 or the chemical formula 3.

  The secondary amino coupling agent may be represented by any one of the following chemical formulas 4 to 6.

In Formula 4,
R ^a , R ^b , R ^d and R ^e may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ^c and R ^f may be the same or different from each other, and each is an alkylene group having 1 to 20 carbon atoms;
In the alkylene group, 1 to 2 —CH ₂ — that are not adjacent to each other are —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or carbon. An arylene group having 6 to 10 carbon atoms may be substituted, and any hydrogen of the arylene group may be substituted with an alkyl group having 1 to 4 carbon atoms;
n and m are each an integer of 0-2.

In Formula 5,
R ^g , R ^h , R ^j and R ^k may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ⁱ , R ^o and R ^p may be the same or different from each other, and each is an alkylene group having 1 to 20 carbon atoms;
In the alkylene group, 1 to 2 —CH ₂ — that are not adjacent to each other are —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or carbon. An arylene group having 6 to 10 carbon atoms may be substituted, and any hydrogen of the arylene group may be substituted with an alkyl group having 1 to 4 carbon atoms;
n and m are each an integer of 0-2.

In Formula 6,
R ^q , R ^r and R ^t may be the same or different from each other and each is a hydrocarbon group having 1 to 8 carbon atoms;
R ^s is an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — that are not adjacent to each other are —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or carbon. An arylene group having 6 to 10 carbon atoms may be substituted, and any hydrogen of the arylene group may be substituted with an alkyl group having 1 to 4 carbon atoms;
m is an integer of 0-2.

  Specific examples of preferred primary or secondary amino coupling agents include dimethylamine, diethylamine, dipropylamine, dibutylamine, and azetidine. ), Pyrrolidine, Piperidine, Cyclopropylamine, Cyclobutylamine, Cyclopentylamine, Cycloamine2 -Azetidinone), 2-pyrrolidinone (2 Pyrrolidinone), 2-piperidinone (although Piperidinone), and the like, but is not limited thereto.

  Further examples of the secondary amino coupling agent include bis (3-trimethoxysilylpropyl) amine (Bis (3-trimethoxysilylpropyl) amine), bis (3-triethoxysilylpropyl) amine (Bis (3 -Triethylsilylpropyl) amine), bis (3-trimethoxysilylpropyl) ethylenediamine (Bis (3-trimethoxysilylpropyl) ethylenediamine), bis (3-triethoxysilylpropyl) ethylenediamine (Bis (3-triethylpropylene) propylene) N- (n-butyl) -3-aminopropyltrimethoxysilane (N- (n-butyl)- -Aminopropyl trimethylsilane, N- (n-butyl) -3-aminopropyltriethoxysilane (N- (n-butyl) -3-aminopropyl trisilane), N-methylaminopropyltrimethoxysilane (N- Examples include, but are not limited to, methyl amino propyl trisilane, N-methyl amino propyl triethoxy silane, and the like.

  The most preferred primary or secondary amino coupling agents can be represented by the following chemical formulas 7-1 to 7-4.

  The primary or secondary amino coupling agent mixed with the polymerizable reactive vertically aligned liquid crystal mixture solution may include 0.01 to 10 parts by weight based on the reactive vertically aligned liquid crystal mixture solution. preferable. When the content of the amino coupling agent is less than 0.01 parts by weight, the adhesive strength is poor, and when it exceeds 10 parts by weight, the alignment state of the liquid crystal is deteriorated.

  The polymerizable reactive vertically aligned liquid crystal mixture solution used in the present invention may further include a surfactant, a photoinitiator, a reactive liquid crystal monomer, and a solvent.

  Surfactants that can be used include fluorocarbon and silicon. Examples of the fluorocarbon-based surfactant include Fluorad (trade name) FC4430, Fluorad FC4432, and Fluorad FC4434 manufactured by 3M of the United States, and Zonyl manufactured by Dupont of the United States. Examples include BYK (trade name) manufactured by the company.

  At this time, the content of the surfactant is preferably 0.05 to 1 part by weight based on the polymerizable reactive vertically aligned liquid crystal mixture solution. When the surfactant content is less than 0.05 parts by weight, the surface condition of the liquid crystal is poor, and when it exceeds 1 part by weight, surfactant micelles are generated due to excessive loading, and the stain is generated. Occur.

  Photoinitiators can be divided into free radical photoinitiators and photoinitiators that generate ions, depending on the type of substance that initiates the polymerization reaction. Examples of free radical photoinitiators include Swiss Ciba-Geigy. Irgacure (trade name) 907, Irgacure 651, Irgacure 184 and the like manufactured by the company, and examples of the cationic photopolymerization initiator include UVI (trade name) 6974 manufactured by Union Carbide of the United States.

  The content of the photoinitiator is preferably 1 to 10 parts by weight based on the polymerizable reactive vertically aligned liquid crystal mixture solution. When the content of the photoinitiator is less than 1 part by weight, the liquid crystal is uncured, and when it exceeds 10 parts by weight, the liquid crystal alignment is deteriorated.

  The reactive liquid crystal monomer is not particularly limited as long as it forms a polymer by polymerizing with a peripheral liquid crystal monomer by light or heat. An example of a reactive group that causes a polymerization reaction of such a reactive liquid crystal monomer includes one having an acrylate attached thereto. Specific examples of the reactive liquid crystal monomer include reactive liquid crystal monomers represented by the following chemical formulas 8 to 12, and one or more selected from the group consisting of the following chemical formulas 8 to 12 can be used. .

  When the reactive liquid crystal monomer is dissolved in the solvent, the solid content concentration varies depending on the thickness of the liquid crystal layer to be obtained and the coating method, but is not particularly limited, preferably 5 to 70% by weight, more preferably 10 to 50%. It is about wt%.

  For reference, when the concentration of the solid content is less than 5% by weight, the drying time becomes longer due to the large amount of the solvent, or the stain becomes severe due to the intense flow of the surface after coating. If it is greater than or equal to the weight percent, the amount of solvent is less than the solid content, so that liquid crystal is precipitated during storage, or the viscosity is too high, resulting in poor wettability during coating. is there.

  The solvent contained in the reactive vertical alignment liquid crystal mixture solution polymerizable with the surfactant, the photoinitiator and the reactive liquid crystal monomer mentioned above is excellent in solubility and coating property with the liquid crystal mixture, and is used as a base material during coating. The type is not particularly limited as long as it does not corrode.

  Specific examples of such solvents include halogenated hydrocarbons such as chloroform, dichloromethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, and chlorobenzene; aromatics such as benzene, toluene, xylene, methoxybenzene, and 1,2-dimethoxybenzene. Hydrocarbons; alcohols such as acetone, methyl ethyl ketone, cyclohexanone and cyclopentanone; cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; ethers such as diethylene glycol dimethyl ether (DEGDME) and dipropylene glycol dimethyl ether (DPGDME) However, the present invention is not limited thereto, and the solvent can be used in the form of a single substance or a mixture.

  Next, a plastic substrate suitable for use in the present invention will be described. Examples of plastic substrates that are easy to bond and align the polymerizable liquid crystal composition include cycloolefin polymers such as polyethylene terephthalate, polycarbonate, polyethylene, norbornene derivatives, and these plastic substrates are widely used industrially. Can be easily obtained from various companies.

  In the case of a plastic substrate to which a roll-to-roll process can be applied, corona discharge treatment or plasma treatment for imparting hydrophilicity to the surface may be performed.

  Such plastic substrates are very advantageous in terms of mass productivity such as roll-to-roll production and high-speed production because many products are excellent in terms of flexibility and durability.

  Hereinafter, a polymerizable liquid crystal composition containing a primary or secondary amino coupling agent according to the present invention on a plastic substrate having a surface subjected to hydrophilic treatment such as corona discharge treatment or plasma treatment as described above. A specific production process for obtaining a vertically aligned liquid crystal layer excellent in alignment force and adhesive force by coating is as follows.

  First, a method of coating the polymerizable liquid crystal composition containing the primary or secondary amino coupling agent on the plastic substrate is not particularly limited, but a method capable of coating with a uniform thickness is preferable. Examples of such coating methods include spin coating, micro gravure coating, gravure coating, dip coating, and spray coating.

  The thickness of the vertically aligned liquid crystal film layer varies depending on the retardation to be obtained, that is, Δn (birefringence index) × d (thickness of the liquid crystal layer), but is generally preferably about 0.1 μm to 10 μm.

  As a method for removing the solvent from the polymerizable liquid crystal composition solution coated on the substrate at a predetermined concentration by the coating method, the solvent can be almost removed, and the coated liquid crystal layer flows or is severely damaged. There is no particular limitation as long as the method does not flow. In general, methods such as room temperature drying, drying in a drying oven, drying by heating on a heating plate, and drying using infrared rays can be used.

  After evaporating the solvent, a step of curing the vertically aligned liquid crystal layer by polymerization is necessary, and the method of curing the liquid crystal is largely divided into light curing and heat curing. The liquid crystal mixture used in the present invention is a photoreactive liquid crystal mixture and is a substance that is fixed by ultraviolet irradiation.

  At this time, the polymerization process may be performed in the presence of a photoinitiator that absorbs wavelengths in the ultraviolet region, and the ultraviolet irradiation may be performed in the air, or may be performed in a nitrogen atmosphere to increase the reaction efficiency by blocking oxygen. Good.

As the ultraviolet irradiator, a medium pressure or high pressure mercury ultraviolet lamp or a metal halide lamp having an illuminance of about 100 mW / cm ² or more is usually used.

  In addition, a cold mirror or a cooling device may be installed between the base material and the ultraviolet lamp so that the surface temperature of the liquid crystal layer is within the range of the liquid crystal temperature when irradiated with ultraviolet rays.

  There are various methods for measuring the presence / absence of vertical alignment of the liquid crystal film and the quantitative retardation value obtained by the above method. The presence or absence of vertical alignment of the liquid crystal film can be confirmed through the naked eye or a polarizing microscope between the orthogonal polarizing plates.

  In other words, a liquid crystal film is positioned between orthogonal polarizing plates, and the vertically aligned liquid crystal layer does not generate a phase difference when observing from the direction perpendicular to the film surface. If you observe the camera while tilting the angle, a phase difference will occur, so light transmission will appear and it will appear bright.

  At this time, the quantitative phase difference value in the direction inclined from the vertical incident angle to a specific angle is calculated by KOBRA-21ADH (manufactured by Oji Scientific Instruments) or AxoScan (automatic birefringence measuring device). Axometrics) can be used.

  The vertically aligned liquid crystal film coated on the plastic substrate according to the present invention is applied as it is to the polarizing plate without being peeled off, and is very useful as a retardation film or a viewing angle compensation film in various forms of LCD modes such as the IPS mode. Used for.

  Hereinafter, preferred examples will be presented to help the understanding of the present invention. However, the following examples are merely for illustrating the present invention, and the scope of the present invention is not limited to the following examples.

<Example 1>
The liquid crystal monomers contained in the polymerizable reactive vertically aligned liquid crystal mixture solution used in the examples of the present invention are represented by the above chemical formulas 8 to 12.

  The compound of the chemical formula 8 is prepared by the method described in GB 2,280,445. J. et al. Broer et al. [Makromol. Chem. 190, 3201-3215 (1989)], and the compound of Formula 11 was prepared by the method described in WO93 / 22397. A polymerizable reactive vertically aligned liquid crystal mixture (LC1) was prepared as follows.

  The polymerizable vertical alignment liquid crystal mixture (LC1) that can be polymerized is placed in toluene so as to have a solid concentration of 25% by weight, and then heated at 50 ° C. for 1 hour to polymerize the reactive vertical alignment liquid crystal that can be polymerized. A mixture solution was prepared.

  Fluorad (trade name: manufactured by 3M, USA) FC4430, a fluorocarbon surfactant, is added to the polymerizable reactive vertically aligned liquid crystal mixture solution so as to be 0.3 parts by weight based on the liquid crystal mixture solution. did.

  Finally, an amino coupling agent (3-propylamine) represented by the chemical formula 7-1 was added so as to be 1 part by weight based on the reactive vertical alignment liquid crystal mixture solution.

  As the substrate for coating the polymerizable liquid crystal composition, a norbornene derivative film, Zeoror (trade name: manufactured by Zeon, Japan) was used after corona discharge treatment.

  A polymerizable reactive vertically aligned liquid crystal mixture solution containing an amino coupling agent represented by the chemical formula 7-1 was coated using a wire bar coater, left in a drying oven at 50 ° C. for 2 minutes, and then 80 W / It was cured once at a speed of 3 m / min using a cm high pressure mercury lamp. The produced liquid crystal film was very transparent and had a thickness of 1 μm.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all. Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  According to FIG. 2, there is no phase difference due to the liquid crystal in the vertical direction of the film, and the phase difference increases as the viewing angle increases, and the − and + directions of the viewing angle are symmetric with each other. It can be seen that the liquid crystal molecules of the film are liquid crystal films oriented in a direction perpendicular to the film surface.

<Example 2>
A polymerizable reactive vertically aligned liquid crystal mixture (LC2) was prepared as follows.

  A liquid crystal film was obtained by the same method as in Example 1 except that the polymerizable reactive vertically aligned liquid crystal mixture (LC2) was used, and the produced liquid crystal film was very transparent and had a thickness of 1 μm. there were.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Further, in order to investigate the optical characteristics of the liquid crystal film, the phase difference of the liquid crystal film bonded on the base material is measured using AxoScan (manufactured by Axometrics), and the liquid crystal film is oriented in the vertical direction. I understand.

<Example 3>
A liquid crystal film was obtained by the same method as in Example 1 except that an amino coupling agent represented by the chemical formula 7-2 was used. The produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  FIG. 3 shows that this liquid crystal film is a liquid crystal film oriented in the vertical direction.

<Example 4>
A liquid crystal film was obtained by the same method as in Example 2 except that an amino coupling agent represented by the chemical formula 7-2 was used. The produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Further, in order to investigate the optical characteristics of the liquid crystal film, the phase difference of the liquid crystal film bonded on the base material is measured using AxoScan (manufactured by Axometrics), and the liquid crystal film is oriented in the vertical direction. I understand.

<Example 5>
A liquid crystal film was obtained by the same method as in Example 1 except that the amino coupling agent represented by the chemical formula 7-3 was used, and the produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  FIG. 4 shows that this liquid crystal film is a liquid crystal film oriented in the vertical direction.

<Example 6>
A liquid crystal film was obtained by the same method as in Example 2 except that an amino coupling agent represented by the chemical formula 7-3 was used, and the produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Further, in order to investigate the optical characteristics of the liquid crystal film, the phase difference of the liquid crystal film bonded on the base material is measured using AxoScan (manufactured by Axometrics), and the liquid crystal film is oriented in the vertical direction. I understand.

<Example 7>
A liquid crystal film was obtained by the same method as in Example 1 except that the amino coupling agent represented by Chemical Formula 7-4 was used. The produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  FIG. 5 shows that this liquid crystal film is a liquid crystal film oriented in the vertical direction.

<Example 8>
A liquid crystal film was obtained by the same method as in Example 2 except that an amino coupling agent represented by the chemical formula 7-4 was used. The produced liquid crystal film was very transparent and had a thickness of 1 μm. Met.

  The liquid crystal film produced in this way had a structure as shown in FIG. 1, was very excellent in bonding strength, and was not peeled off from the substrate at all.

  Further, in order to investigate the optical characteristics of the liquid crystal film, the phase difference of the liquid crystal film bonded on the base material is measured using AxoScan (manufactured by Axometrics), and the liquid crystal film is oriented in the vertical direction. I understand.

<Comparative Example 1>
A liquid crystal film was obtained by the same method as in Example 1 except that an amino coupling agent was not used for the liquid crystal, and the produced liquid crystal film was transparent and had a thickness of 1 μm.

  However, in the liquid crystal film thus produced, a large number of craters were observed (diameter: about 100 μm), and because the bonding force was very poor, the liquid crystal film was completely peeled off from the substrate.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  FIG. 6 shows that this liquid crystal film is a liquid crystal film oriented in the vertical direction.

<Comparative example 2>
A liquid crystal film was obtained by the same method as in Example 2 except that an amino coupling agent was not used for the liquid crystal, and the produced liquid crystal film was transparent and had a thickness of 1 μm.

  However, in the liquid crystal film thus produced, a large number of craters were observed (diameter: about 100 μm), and because the bonding force was very poor, the liquid crystal film was completely peeled off from the substrate.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  FIG. 7 shows that this liquid crystal film is a liquid crystal film oriented in the vertical direction.

<Comparative Example 3>
A liquid crystal film was obtained by the same method as in Example 1 except that 3-aminopropyltrimethoxysilane, which is a primary aminosilane-based coupling agent, was used for the liquid crystal, and the produced liquid crystal film was opaque and thick. The thickness was 1 μm.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  The liquid crystal film manufactured in this way has excellent bonding strength, but has a problem in vertical alignment and birefringence (Δn) is reduced.

<Comparative example 4>
A liquid crystal film was obtained in the same manner as in Example 2 except that 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane), which is a primary aminosilane coupling agent, was used for the liquid crystal. The liquid crystal film was opaque and the thickness was 1 μm.

  Moreover, in order to investigate the optical characteristic of a liquid crystal film, the phase difference of the liquid crystal film couple | bonded on the base material was measured using AxoScan (made by Axometrics), and the result is shown in FIG.

  The liquid crystal film manufactured in this way has excellent bonding strength, but has a problem in vertical alignment and birefringence (Δn) is reduced.

  Table 1 below compares the orientation and adhesive strength of the samples.

  With the polymerizable liquid crystal composition according to the present invention, a primary or secondary amino coupling agent is added to an existing polymerizable reactive vertical alignment liquid crystal mixture solution, regardless of the presence or absence of an alignment film. Since a stable vertical alignment liquid crystal film can be produced, productivity is greatly improved.

Claims (19)

A polymerizable liquid crystal composition comprising a polymerizable reactive vertically aligned liquid crystal mixture and a secondary amino coupling agent represented by any one of the following chemical formulas 4 to 6 .

In Formula 4,
R ^a , R ^b , R ^d and R ^e may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ^c and R ^f may be the same or different from each other, each being an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
n and m are each an integer from 0 to 2;

In Formula 5,
R ^g , R ^h , R ^j and R ^k may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ⁱ , R ^o and R ^p may be the same or different from each other, and each is an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
n and m are each an integer from 0 to 2;

In Formula 6,
R ^q , R ^r and R ^t may be the same or different from each other and each is a hydrocarbon group having 1 to 8 carbon atoms;
R ^s is an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
m is an integer of 0-2.   The secondary amino coupling agents include bis (3-trimethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) amine, bis (3-trimethoxysilylpropylethylenediamine) and bis (3-triethoxysilyl). Propyl) ethylenediamine, N- (n-butyl) -3-aminopropyltrimethoxysilane, N- (n-butyl) -3-aminopropyltriethoxysilane, N-methylaminopropyltrimethoxysilane, and N-methylamino The polymerizable liquid crystal composition according to claim 1, wherein the polymerizable liquid crystal composition is one selected from the group consisting of propyltriethoxysilane. The polymerizable liquid crystal composition according to claim 1, wherein the secondary amino coupling agent is represented by the following chemical formula 7-4 .

The polymerizable liquid crystal composition according to claim 1 , wherein the polymerizable reactive vertically aligned liquid crystal mixture further includes a reactive liquid crystal monomer, a surfactant, a photoinitiator, and a solvent. The polymerizable liquid crystal composition according to claim 4 , wherein the reactive liquid crystal monomer is at least one selected from compounds represented by the following chemical formulas 8 to 12.

The polymerizable liquid crystal composition according to claim 4 , wherein the surfactant includes any one of a fluorocarbon-based or silicon-based surfactant. The polymerizable liquid crystal composition according to claim 4, wherein the surfactant contains 0.05 to 1% by weight based on the polymerizable reactive vertically aligned liquid crystal mixture. The solvent is chloroform, dichloromethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, methyl cellosolve, ethyl cellosolve, butyl cellosolve. The polymerizable liquid crystal composition according to claim 4, wherein the polymerizable liquid crystal composition is at least one selected from the group consisting of diethylene glycol dimethyl ether (DEGDME) and dipropylene glycol dimethyl ether (DPGDME). A polymerizable vertically-aligned liquid crystal compound and a secondary amino coupling agent represented by any one of the following chemical formulas 4 to 6 are included on a plastic substrate whose surface has been subjected to a hydrophilic treatment. A method for producing a vertically aligned liquid crystal film, comprising a step of coating a polymerizable liquid crystal composition.

In Formula 4,
R ^a , R ^b , R ^d and R ^e may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ^c and R ^f may be the same or different from each other, each being an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
n and m are each an integer from 0 to 2;

In Formula 5,
R ^g , R ^h , R ^j and R ^k may be the same or different from each other, and each is a hydrocarbon group having 1 to 8 carbon atoms,
R ⁱ , R ^o and R ^p may be the same or different from each other, and each is an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
n and m are each an integer from 0 to 2;

In Formula 6,
R ^q , R ^r and R ^t may be the same or different from each other and each is a hydrocarbon group having 1 to 8 carbon atoms;
R ^s is an alkylene group having 1 to 20 carbon atoms,
In the alkylene group, 1 to 2 —CH ₂ — not adjacent to each other is —O—, —NH—, —CH═CH—, —CONH—, a cycloalkylene group having 3 to 8 carbon atoms, or 6 to 10 carbon atoms. Any of the arylene groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
m is an integer of 0-2. The secondary amino coupling agents include bis (3-trimethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl) ethylenediamine, and bis (3-triethoxy Silylpropyl) ethylenediamine, N- (n-butyl) -3-aminopropyltrimethoxysilane, N- (n-butyl) -3-aminopropyltriethoxysilane, N-methylaminopropyltrimethoxysilane, and N-methyl The method for producing a vertically aligned liquid crystal film according to claim 9 , which is one selected from the group consisting of aminopropyltriethoxysilane. The method for producing a vertically aligned liquid crystal film according to claim 9 , wherein the secondary amino coupling agent is represented by the following chemical formula 7-4 .

The method for producing a vertically aligned liquid crystal film according to claim 9, wherein the polymerizable reactive vertically aligned liquid crystal mixture further includes a reactive liquid crystal monomer, a surfactant, a photoinitiator, and a solvent. The method for producing a vertically aligned liquid crystal film according to claim 12 , wherein the reactive liquid crystal monomer is at least one selected from compounds represented by the following chemical formulas 8 to 12.

The method for producing a vertical alignment liquid crystal film according to claim 12 or 13 , wherein the surfactant includes any one of a fluorocarbon-based or silicon-based surfactant. The method for producing a vertical alignment liquid crystal film according to any one of claims 12 to 14, wherein the surfactant contains 0.05 to 1% by weight based on the polymerizable reactive vertical alignment liquid crystal mixture. The solvent is chloroform, dichloromethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, methyl cellosolve, ethyl cellosolve, butyl cellosolve. The method for producing a vertically aligned liquid crystal film according to any one of claims 12 to 15 , which is at least one selected from the group consisting of: diethylene glycol dimethyl ether (DEGDME), and dipropylene glycol dimethyl ether (DPGDME). The said hydrophilic process is a manufacturing method of the vertical alignment liquid crystal film in any one of Claims 9-16 which is a corona discharge process or a plasma process. The vertical alignment liquid crystal film manufactured by the method of any one of Claims 9-17 . A liquid crystal display device comprising a vertically aligned liquid crystal film according to claim 18 .

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